Dietary fiber consists of the non-digestible polysaccharide fractions of plant fiber and is classified as water soluble (pectin or guar), and water insoluble products such as wheat bran. These fibers all have different characteristics and subsequently different metabolic and physiologic effects. The generalized metabolic effects of fiber have been demonstrated in several studies. These include change in the fermentation products and effect on short chain fatty acids in the colon, which effects hepatic glucose and lipid metabolism. Additionally, fiber has been shown to affect gastric emptying and serum insulin responses by a variety of mechanisms resulting in enhanced peripheral receptor site sensitivity to insulin. Because of the changes noted in carbohydrate absorption and metabolism, fiber has been studied as a supplemental treatment of diabetes mellitis.
The roles of dietary fiber as an alexeteric for protecting the gastrointestinal tract from diseases have also been documented. These include reduction in gastrointestinal cancer incidence, constipation, hiatal hernia, appendicitis, diverticular disease, and hemorrhoids. There are also implications of its use in the treatment or prevention of "irritable bowel syndrome".
It is known that the loss of branched-chain amino acids in caloric restricted diets is a loss in lean body mass from atrophy of the columnar cells of the gastrointestinal tract, and will lower resting energy expenditure.
Currently, fiber has been implicated in weight reduction diets and is thought to work by various mechanisms. One mechanism proposed is the delay in gastric emptying and faster transit time in the small bowel association with high fiber diets. The adsorption properties of fiber in the gastrointestinal tract have resulted in the lowering of glucose absorption, resulting in lower: serum glucose, insulin levels and gastric inhibitory peptide. The physiologic responses implicate some forms of fiber as an active pharmacologic agent in appetite suppression and hyperglycemia. The physical bulk effect of the agent, increasing gastric distention, may also explain earlier satiety.
The effect of fiber on fat absorption has led to several studies indicating the advantages of high fiber diets in reduction of serum cholesterol levels and weight loss in the treatment of hypertension.
Sugar beet pulp, as presently obtained, is a product of the sugar beet refining process and contains 48% pectin by weight under current methods of extraction and has a coefficient of expansion of about 2 in aqueous solutions.
A study by Tredger, Sheard and Marks, "Blood Glucose and Insulin Levels in Normal Subjects Following a Meal With and Without Added Sugar Beet Pulp" in Diabete & Metabolisme (Paris), 1981, 7, 169-172, concluded that:
"--both on the grounds of efficacy and acceptability our studies suggest it is unlikely that sugar beet pulp has any part to play in the dietary management of diabetic patients".